The project is aimed at investigating the dynamic behavior of the spinal cord under impact loading and to quantify the mechanical responses of the cord in relationship with the irreversible and reversible injury of the spinal cord. The main focus will be placed upon the transmission of impact force and energy to the spinal cord during the impact; the amount of protection provided by tissues and vertebrae; the damping and shock-absorbing mechanism of the cerebral spinal fluid; the deformation and its rate of the spinal cord, the propagation of stress waves during the impact, and the stress-strain relationship of the cord. The project will be oriented primarily toward the biomechanical understanding of laboratory induced impact injury on animals in order to gain insight for the clinical and therapeutic studies of spinal cord injury. Our approach is to quantify the dynamic behavior of the spinal cord for cases when the impact force is acting on the intact vertebral column as well as on a laminectomized cord. For the latter case, the cord will be tested also for cases when the CSF is partially or totally removed. The biomechanical characteristics of the spinal cord can be better understood if the mechanical response is correlated with different magnitudes of impact forces. Also, mathematical models will be developed to analyze the biomechanics of the spinal cord injury. The study will provide a definite relationship between the impact loading and morphological damages in the spinal cord.